Facebook has confirmed that it has hired George Hotz, a celebrated hacker known as "GeoHot" who was sued by Sony for hacking the Japanese company's PlayStation 3 game console.

A Facebook spokeswoman confirmed in an email to AFP that Hotz had been hired by the social network but declined to say when he had started or what he was doing for the Palo Alto, California-based company.

Hotz, who is credited with being the first person to go public with a way to hack into an iPhone, reached a settlement with Sony in April in the PS3 hacking case.

Sony had accused Hotz of violating federal law by posting online information that could be used to circumvent the PS3 security system and allow for play of pirated videogames.

In mid-April, internet vigilante group Anonymous began staging cyberattacks on Sony's online services, including the PlayStation Network, in retaliation for the legal action against Hotz and another hacker, Alexander Egorenkov.

Anonymous argued that PS3 console owners have the right to do what they wish with their consoles, including modifying them.

Sony's PlayStation Network, Qriocity music streaming service and Sony Online Entertainment were among the online services targeted in cyberattacks and data breaches which compromised more than 100 million accounts.

Tim Schaaff, president of Sony Network Entertainment International, said Wednesday that the level of activity on the PlayStation Network had returned to more than 90 percent of what it was before the cyberattacks began in April.